To prepare a detergent for body, providing excellent foam properties (creamy properties), hardly causing sticky feeling after use thereof, and excellent in sense of use by including a specific acetylated hyaluronic acid.

The objective cosmetic contains an acetylated hyaluronic acid having 2-4 number of substitution by acetyl groups in a repeating structural unit of the formula (R1 to R4 are each H or acetyl bonded with an ester bond with the proviso that two or more of the R1 to R4 are acetyl; R5 is H or an alkali metal), preferably of 0.0001-10 wt.%, more preferably of 0.001-5 wt.%.